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STUDY OF THE INFLUENCE OF MICROWAVE PREASSURE TREATMENT ON THE EXTRACTION OF REFRACTORY GOLD Fuzaylov O.U. (Republic of Uzbekistan) Email: [email protected]
Fuzaylov Omon Ubaydulloyevich - PhD Student, METALLURGY DEPARTMENT, NAVOI STATE MINING INSTITUTE, NAVOI, REPUBLIC OF UZBEKISTAN
Abstract: the paper presents the results of microwave pressure treatment of the raw and microwave roasted refractory flotation concentrate in order to study its effect. Investigation on microwave pressure treatment of refractory gold concentrate before and after roasting has shown significant improvements in gold recovery. The influence of temperature, pH of the medium and the content of hydrogen peroxide as an oxidizing agent were investigated. The results showed that additional microwave pressure treatment of the roasted concentrate for 60 minutes at 200 °C, pH = 2 can increase the extraction rate of gold for an additional ~ 15%.
Keywords: refractory concentrate, gold, microwave, pressure treatment, extraction rate, roasting, encapsulated gold.
ИССЛЕДОВАНИЕ ВЛИЯНИЯ МИКРОВОЛНОВОЙ АВТОКЛАВНОЙ ОБРАБОТКИ НА ИЗВЛЕЧЕНИЕ УПОРНОГО ЗОЛОТА Фузайлов О.У. (Республика Узбекистан)
Фузайлов Омон Убайдуллоевич - докторант, кафедра металлургии, Навоийский государственный горный институт, г. Навои, Республика Узбекистан
Аннотация: в статье представлены результаты микроволновой автоклавной обработки исходного и обожженного микроволнами упорного флотационного концентрата с целью изучения его влияния. Исследование микроволновой автоклавной обработки упорного концентрата золота до и после обжига показало значительные улучшения в извлечении золота. Было исследовано влияние температуры, pH среды и содержания перекиси водорода как окислителя. Результаты показали, что дополнительная микроволновая автоклавная обработка обожженного концентрата в течение 60 минут при 200 °С, pH = 2 может увеличить степень извлечения золота на ~ 15%.
Ключевые слова: упорный концентрат, золото, микроволны, обработка под давлением, степень извлечения, обжиг, капсулированное золото.
The method of processing under pressure at temperatures above the boiling point of the solution and, therefore, at pressures above atmospheric, characterizes the pressure treatment. Pressurization above the boiling point releases the encapsulated gold grains from non-porous minerals and makes the ore or concentrate residue more amendable for gold recovery by cyanidation in a subsequent leaching step. Therefore, pressure treatment of gold-bearing ores is a pre-leach step to enhance gold recovery.
Investigation on microwave pressure treatment of refractory gold concentrate before and after roasting has shown significant improvements in gold recovery.
The influence of temperature, pH of the medium and the content of hydrogen peroxide as an oxidizing agent were investigated.
As the results show (table. 1.), hydrogen peroxide does not have a significant effect on the extraction rate of gold from the roasted concentrate, but according to the results No 10; 11; 12 a slight increase is noticed in the extraction rate of gold from the raw flotation concentrate with an
increase in the content of hydrogen peroxide. With regard to the pH of the medium, in all samples, pH = 2 can be set as the optimal acidity parameter.
According to all the results, it is clear that temperature has a positive effect on the extraction that at 200 ° C the rate of gold extraction reaches to 90%.
Table 1. Results of microwave pressure treatment of the raw and MW roasted flotation concentrate
No pH т, min. Т, °С Р, atm. Content H2O2, g/l £, % (from initial concentrate) £, % (roasted concentrate)
1 1 30 150 ~ 5 0,0 43,4 78,6
2 2 30 150 ~ 5 0,0 52,2 79,5
3 3 30 150 ~ 5 0,0 50,6 78,4
4 1 60 180 ~ 10 1,5 52,3 84,5
5 2 60 180 ~ 10 1,5 52,4 84,8
6 3 60 180 ~ 10 1,5 52,3 82,4
7 1 90 200 ~ 15 3,0 52,5 89,8
8 2 90 200 ~ 15 3,0 52,1 89,8
9 3 90 200 ~ 15 3,0 52,2 88,7
10 2 60 200 ~ 15 0,0 51,2 89,6
11 2 60 200 ~ 15 1,5 52,6 89,8
12 2 60 200 ~ 15 3,0 52,8 89,5
Figure 1. clearly shows a sharp change in the degree of gold recovery at 200 °C, which indicates a change in the structure of minerals, which caused the release of the surface of gold particles.
Fig. 1. Change in the extraction rate of gold in time at temperatures: 150°C; 180°C; 200°C
Thus, the results of cyanidation sorption of the treated concentrate showed that additional pressure treatment of the roasted flotation concentrate for 60 minutes at 200 °C, pH = 2 can increase the gold extraction rate for an additional ~ 15%.
References / Список литературы
1. Азимов О.А., Ермаков С.В., Лесков С.Ф., Плотникова А.В. Модель расчета гранулометрического состава минерального сырья при его измельчении с использованием магнитно-импульсной обработки // Горный информационно-аналитический бюллетень. Отдельные статьи, 2009. № 11. С. 3-9.
2. Санакулов К.С., Фузайлов О.У., Кенбаева Ж.А. Микроволновая обработка сульфидных золотосодержащих концентратов // Горный вестник Узбекистана, 2020. № 1. C. 53-56.
